The effect of COVID-19 on blood donation habits.

BACKGROUND: Blood centers (BCs) rely on schools and businesses. Shelter-in-place orders closed them. This study determined how COVID-19 affected donation habits. STUDY DESIGN AND METHODS: Two periods were reviewed (May 1 through June 30, 2018 vs 2019 [control] and 2019 vs 2020 [study-COVID period]). These donations were reviewed: first-time, repeat (donation ≤ 2 years), and lapsed (no donation > 2 years); sex; age; ethnicity; and ABO blood groups at high school and college drives. Testing all donors for SARS-CoV-2 antibodies started May 18, 2020. RESULTS: In the study period donations significantly increased (control P = .683, study P ≤ .0001) and comparing sex (control male P = .716, female P = .657; study male P = .004, female P ≤ .0001). In the study period there was a significant decrease in Hispanic (P = .001) and African American (P < .0001) donations also seen among high school and college drives and an increase in Caucasian (P < .0001) donations. There was a significant increase in first-time (P < .0001) and lapsed donors (P < .0001) in the study period vs control (first-time P = .087, lapsed P = .308) and a significant decrease in donors not more than 30 years (study 16-20 P < .0001, 21-30 P < .0001). There was a significant increase in all blood types in the study period (P < .0001) and in donations after implementation of SARS-CoV-2 antibody testing (P = .001). CONCLUSIONS: Significant changes occurred in donation habits in the study vs the control periods. These included increased total donations, comparing sexes, first-time and lapsed donors, all blood types, and Caucasian donations. Significant decreases were seen in Hispanic and African American donations and those not more than 30 years old.

Selecting COVID-19 convalescent plasma for neutralizing antibody potency using a high-capacity SARS-CoV-2 antibody assay.

BACKGROUND: Efficacy of COVID-19 convalescent plasma (CCP) is hypothesized to be associated with the concentration of neutralizing antibodies (nAb) to SARS-CoV-2. High capacity serologic assays detecting binding antibodies (bAb) have been developed; nAb assays are not adaptable to high-throughput testing. We sought to determine the effectiveness of using surrogate bAb signal-to-cutoff ratios (S/Co) in predicting nAb titers using a pseudovirus reporter viral particle neutralization (RVPN) assay. METHODS: CCP donor serum collected by three US blood collectors was tested with a bAb assay (Ortho Clinical Diagnostics VITROS Anti-SARS-CoV-2 Total, CoV2T) and a nAb RVPN assay. Prediction effectiveness of various CoV2T S/Co criteria was evaluated for RVPN nAb NT50 titers using receiver operating characteristics. RESULTS: Seven hundred and fifty-three CCPs were tested with median CoV2T S/Co and NT50 of 71.2 of 527.5. Proportions of donors with NT50 over target nAb titers were 86% ≥1:80, 76% ≥1:160, and 62% ≥1:320. Increasing CoV2T S/Co criterion reduced the sensitivity to predict NT50 titers, while specificity to identify those below increased. As target NT50 titers increase, the CoV2T assay becomes less accurate as a predictor with a decline in positive predictive value and rise in negative predictive value. CONCLUSION: Selection of a clinically effective nAb titer will impact availability of CCP. Product release with CoV2T assay S/Co criterion must balance the risk of releasing products below target nAb titers with the cost of false negatives. A two-step testing scheme may be optimal, with nAb testing on CoV2T samples with S/Cos below criterion.

Novel Example of a Direct-Agglutinating Anti-Ku.

BACKGROUND: Several Kell-system antibodies are known to cause direct agglutination. Also, some specificities, such as anti-Ku, have been reported to react only via the indirect antiglobulin test (IAT). METHODS: Herein, we describe the case of a 61-year-old alloimmunized white woman who presented to an outside hospital with a gastrointestinal (GI) bleed and a "possible anti-Ku" was reported with 3+ reactivity at PEG-IAT and at Ficin-IAT; in addition to an unidentified cold antibody. Subsequently, when the patient presented to a second outside hospital, an anti-Ku that caused 3+ to 4+ reactions at saline-immediate spin (IS) was identified. The reactivity was evaluated with 0.01-M dithiothreitol (DTT) treatment of the plasma. RESULTS: It was determined that the strong agglutination with saline-IS was caused by immunoglobulin (Ig)M anti-Ku. CONCLUSION: To our knowledge, this is the first reported case of an IgM anti-Ku.